A Rat Model of Acute Bacterial Rhinosinusitis Induced by Staphylococcus Aureus

Kim, Hyun Soung; Jeon, Sea Yuong; Ahn, Seong Ki; Kim, Jin Pyeong; Park, Jung Je; Jeong, Jae Ho; Sung, Byung Gi; Kang, Yune Sik

Abstract

BACKGROUND AND OBJECTIVES
An experimental model of bacterial rhinosinusitis is essential to study the pathogenesis of rhinosinusitis. To our knowledge, there hasn't been an experimental model using rats for bacterial rhinosinusitis, where Staphylococcus aureus is directly inoculated to the rat nose. Staphylococcus aureus is also a predominantly isolated bacterial pathogen in the episode of acute rhinosinusitis. The aim of this study was to develop a rat model of rhinosinusitis induced by Staphylococcus aureus, ATCC 25923. SUBJECTS AND METHOD: The infected Sprague-Dawley rats (4-6 week-old male) were applied intranasally with 40 microliter of Staphylococcus aureus, ATCC 25923, which corresponds to 108 colony-forming units per milliliter, which in turn corresponds to a No. 1 McFarland turbidity by spectrophotometer (VITEK, USA). After the 2nd, 5th, and 14th day, the rats were killed respectively. RESULTS: Nasal sinuses were then observed at low power field (x40) for changes in the amount of inflammatory cell clusters in the sinus cavity. There were significant differences in the number of inflammatory cell clusters between the infected and control rats (p<0.05). The infected rats killed at the 5th day had significantly more inflammatory cell clusters within the sinus cavities (p<0.05). CONCLUSION: Staphylococcus aureus induces acute bacterial rhinosinusitis in rats as measured by increased inflammatory cell clusters. This study demonstrates the efficacy of a rat model of acute bacterial rhinosinusitis.